ABS and DSC lights randomly come on and off

My thoughts were either ABS module is bad or maybe ABS sensors at the wheels are bad. I have a little hand held code reader but it's not registering any codes so I'm stumped on where to start. Any guidance would be appreciated. Thanks!

You need a special tool for ABS. Most code readers only scan the ECU.
My money is on a bad sensor.
First check for breaks in the wire.
It will be difficult to troubleshoot until the ABS light is always on.

I had a constant ACS, DSC on my Mini.
Cleaned all the sensors. Didn't fix it.
Bought 1 new sensor. Replaced the left side. Still bad.
Took the one I removed and swapped it with the right. Bingo.
Trial and error unless you can get the codes scanned.